The first of 706 cars the agency has ordered from Canadian-based Bombardier took to the Pink line Tuesday. As more cars are produced and shipped, they'll be tested internally to ensure all components are operating properly before going into service, the CTA said.

"You can't run a 21st Century economy on 20th Century infrastructure, and this is another down-payment on bringing the CTA into the 21st Century," said Mayor Rahm Emanuel, who toured the new cars prior to an inaugural run.

The Series 5000 cars have fewer seats and will be aisle-facing, but they'll offer more room for standing passengers. Other new features that passengers will notice include: lights indicating which doors to use, security cameras, digital displays with maps and route information and better climate controls.

The new cars also have a environmentally-friendly element: energy from the brakes on the new cars is collected and fed back to the third-rail, saving money and reducing their carbon footprint.

The addition of the new cars will allow CTA to retire some of its cars, which average between 32 and 41 years old, the authority said.

"Modernizing the fleet is very important and is fiscally prudent because a younger fleet requires less maintenance and allows CTA to keep the trains on the system where they are needed and not in the repair shop," said CTA President Forrest Claypool.

Through 2014, the CTA will be add a six-car train every two weeks to the Pink, Green, Red, Orange, Yellow and Purple lines, in that order. There was no mention of the Brown Line, but it recently underwent a multi-year, multi-million dollar facelift.

The total cost of the rail cars $1.137 billion, funded by two CTA bond issuances backed by sales tax receipts, with the remaining $150 million paid from federal funds.